Since the cable assemblies only cost pence each, if you've got a serious interest in sourcing them I suggest that getting hold of a few examples from different sources is a no-brainer. This will also enable you to get details of the terminals needed. Also have a trawl through catalogs for digikey and similar suppliers and see if you can recognise them.
If you aren't planning to compete with Yourduino or Seeduino, you have nothing to lose by simply asking them to recommend a supplier. The worst they can do is say 'no'. Then again, perhaps they already have.